Abstract
Hemorrhagic septicemia (HS) is a highly contagious and fatal disease of cattle and buffaloes caused by P. multocida. Both conventional and molecular methods are applied in parallel for rapid diagnosis of HS outbreaks and the periodical surveillance strategy to identify risk areas for HS is ignored. The current cross-sectional study aimed to estimate sero-prevalence and associated risk factors for HS in cattle and buffaloes in non-vaccinated regions of two Indian states. HS surveillance was carried out through the multi-stage random sampling technique at different strata. The study employed a questionnaire incorporating host factors (species, breed, sex, age, and lactation) and demographic parameters (state, district, block/cluster and village/epiunits, and household). First, two Indian states known for high milk production were selected followed by two districts within each state, subsequently four clusters within each district, finally 5-10 epiunits within clusters and 5-8 households within clusters were randomly selected to collect cattle and buffalo samples. The chi-square/p values and maps were prepared to represent disease prevalence and to correlate disease risk factors at different strata. A total of 692 cattle and buffalo serum samples were sourced from two states of the country (Karnataka-285 and Gujarat-407). In the first strata, antibodies to P. multocida were high in Gujarat (14.49%, CI: 11.22-18.30) compared to Karnataka (3.85%, CI: 1.94-6.80) with significant (p < 0.0001) association between the states. In the second strata, one of the four districts investigated revealed the highest sero-prevalence (18.61%, CI: 13.81-24.24) with statistical significance (p = 0.01) between the districts. Among clusters, one out of eight clusters showed the highest sero-prevalence (23.02%, CI: 16.59-30.54) with statistical significance (p = 0.03) between the clusters in the third strata. At epiunit level (fourth strata), 9 out of 27 epiunits (33.33%) visited in Karnataka and 24 out of 29 epiunits sampled in Gujarat were sero-positive (82.75%) in iELISA. At the household level, out of 306 HH visited, 40 HH had at least one positive animal (13.07%) and the p value between HH in the two states was highly significant (p = 0.0002). Chi-square analysis did not find any association of HS sero-prevalence to species, age, and lactation. However, significantly higher (p < 0.05) sero-prevalence was recorded in indigenous cattle breeds (16.56%) compared to crossbreeds (6.59%). Various immunoprophylactics and antibiotic therapies are effective against HS, but inappropriate disease reporting and failure to implement adequate vaccination control measures are the gaps identified. The present study highlights the current scenario of HS sero-prevalence in two of the high milk-producing states of India, which will be useful for stakeholders for undertaking the implementation of surveillance and control strategies for the regions.